Swimming can be a drag

One of the biggest fears of triathlons for many is swimming. This can be overcome. There are several issues with swimming:

 1. I'm afraid of water. Yes I understand that completely. I was having regular panic attacks, breathe coming too fast, chest constricted, feeling like I was going to die. Yes I get water fear totally. The only way to overcome fear is to face it head on. And I do mean head on. Put your face in the water and try. And keep trying. Believe this is overcomeable, that you don't have to live with this fear anymore and that you can do it. Find a patient and friendly coach to help you through the hard parts and who encourages you by celebrating all the small advances you make.
 2. I can't swim at all. I get that too. I could not swim more than 1/2 length in free style. It just made me completely breathless and feeling overwhelmed. I could do a nice breast stroke but as your coach will tell you, breast stroke uses up your legs for the rest of the race. Dang! Back stroke is a good alternative but you can't see where you are going. If you do have a good back stroke though, you can get through most races okay. I have friends who have done it; a full iron man in back stroke. So be undaunted, use the strokes that work for you, develop multiple strokes and find your mojo in the water. The first step is finding the ability to get through the whole race, no matter what distance you choose. Once you have that first race under your belt you can think about refining. It may not be pretty, it may be very slow, but get it done. That builds confidence.
 3. I swim but I'm like molasses. This is where you need more than just swimming. You need to start considering what's holding you back. Surprisingly, it's less about strength than it is about form. You see, swimming is NOT like the other two legs where brute force makes you better. It's more about the finesse and learning to work with the medium of water.

 As a chemical engineer, I did my master's thesis on fluid flows. Thus I may be better situated to analyze what is happening in the water, than some. Below are my annual swim times at races and some 100 yard maximum effort times for the last 6 years.

  2010 Chicago Tri over 1 hour to swim .9 miles
2011 Chicago Tri 45 mins for .9 miles; 100 yds avg 2:20
2012 Chicago Tri, 40 mins for .9 miles; 100 yds avg  2:00, fastest 1:31
2013 Steelhead 45 mins for 1.2 mile; 100 yds avg 1:45, fastest 1:30
2014 Racine 40 mins for 1.2 mile; 100 yds avg 1:35, fastest 1:29
2015 Indoor Tri, 15 mins for .5 mile; 100 yds avg 1:30, fastest 1:27

As you can see I have improved more in the last three years than in the prior two. This is because I began to analyze what was happening in the water and I had a goal to do a full IM in the back of my head. I did not share this until 2015 when it appeared I might be gaining the necessary fitness to get there.

 WHAT IS THE SECRET?
 The secret is understanding how drag affects you in the water. Yep, it sounds simple but it's very complex. This is why there is little written that is simple about this problem. One caveat, what I say may not be completely accurate mathematically or scientifically, but in order to make these complicated issues approachable by athletes with no engineering, I have to ignore some of the details. For those of you who might be interested, there are some citations at the end of this blog for you that are scientifically based. So what is drag? Drag is the opposite force acting on a moving body. Drag on biking can be felt from the crosswinds or headwinds you encounter. Many athletes instinctively will go low to the aero bars to make themselves a smaller and more aerodynamic shape on the bike, reducing drag. Racing wheels take advantage of wind force and reducing drag on the road. But people in the water, where drag is a much larger factor do not seem to have the same instincts. Let's investigate where drag comes from in the water. The figures below show how drag is affecting the body with the arrows that are opposing the direction of swimming.

Figure 1 center of gravity

Figure 2: body rotation

Figure 3, bad form (top) versus good form (bottom)

Figure 1: The first figure above shows how the body is affected by head position. Note: COG = Center of Gravity. Think about a teeter totter. When you put a heavier kid opposite a lighter kid, you have to put the lighter kid out further and the heavier kid in closer to the center of gravity. This same principle is at work in the water. Your body moves around your COG much like a teeter totter and like a teeter totter that is very well balanced, very small changes dramatically affect the position of the body. So if you tend to clench your neck and shoulder muscles and lift your head even slightly, the legs will drop in response. The head is closer to the COG and quite heavy so it has an immediate effect on the body position in the water.  So why is that important? Because at the water surface, the drag is much reduced. For every 30 feet down, the atmospheric pressure doubles in water. This can be translated to: there is a lot more water for every inch you go deeper into the water. That means that you are pushing aside a lot more water or pulling yourself through a lot more water when you let your body dip into deeper water. And because the pressure increases so rapidly, even 3 inches deeper has a significant effect. Thus you need to work on riding on top of the water with your whole body:  Keep your neck muscles relaxed, and your eyes looking mostly down, feel your feet at the surface behind you.

Figure 2: Another aspect of drag is how the body is affected by it when you are moving. Note in figure two that the two diagrams indicate the body as it rotates in free style swimming. Even small amounts of lift from the water, reduce the drag in the water. Drag in air is dramatically less than drag in the water, so lifting your shoulder and arm out, give your body a temporary relief from the drag you are trying to overcome. It's not huge, but over time and long distance, small reductions mean a great deal. I call it "the magic of volume" because if you charge 1 cent for a billion items you make a lot more money than charging $10 for 1000 items. Little effects add up.  So work on your rotation: keep your elbows high and rotate your torso.

Figure 3:  The last diagram shows the body with good position and poor position (plus bad foot position). The bottom of the diagram shows the body at the surface of the water, head down and feet pointed and legs up. Swimming with this position will have the effect of almost "skimming" over the water. The top of the diagram shows how many swimmers are traveling. Head up, feet flexed, and legs sinking. Recall that the deeper you are in the water, the more drag you will have to overcome. With feet flexed you are even deeper and your feet act like an anchor on your travel. Your arms have to pull harder, your feet have to travel through a lot of water to kick and you are basically fighting drag your whole swim. This is why people improve with wetsuits. The wetsuit tends to lift the butt and legs even if you have bad head position. That reduces your drag and makes your swimming less of a battle with the water. However, if you would correct your form, the wetsuit would have an even better effect and you'd be faster yet.  Work on your flexibility:  point your toes, lengthen your body and keep your muscles loose and filled with air.  Imagine that you are skimming on the water.

 There are other effects that I will talk about later, but understanding drag and why form is the most important aspect of swimming will help you to begin to improve your speeds. As you can see from my data above, applying these ideas has helped me to improve from a virtual non-swimmer to challenging swimmers 20 years my junior. I am not stronger than they are, I'm using the forces and reducing drag more efficiently. This is why, when you try really hard, sometimes you will swim slower. Not only do you do things like clench your muscles making them more dense and sinking in the water, but you lift your head as you clench and kick and windmill your arms faster and create turbulence in the water that can really slow you further. You can't muscle your way to more speed. It's counter intuitive but really you need to become Zen and one with the water to slice through it smoothly. Once you master that, applying more muscle becomes effective.

Next time: the effects of turbulence on your swimming.

 I hope this helps you to swim faster too!


Here are a few citations for you:
1.Wave Drag in Front Crawl Swimming, Huub M Touissaint, Stralen and Stevens, Institute of Fundamental and Clinical Human Movement Science, Vrije Universitait, Amsterdam Netherlands, ISBS 2002
2.  Toussaint, H.M. et al. (2000). Biomechanics of swimming. In: Exercise and Sport Science (Garrett, W.E.; Kirkendall, D.T., eds), 639-660. Philadelphia: Lippincott, Williams & Wilkins.
3. Toussaint, H.M., Berg, C.v.d.; Beek, W.J. (2002). Pumped-up propulsion during front crawl swimming. Medicine and Science in Sports and Exercise, 34(2), 314-319.
4.  Kolmogorov S, Duplishcheva . Active drag, useful mechanical power output and hydrodynamic force coefficient in different swimming strokes at maximal velocity. J Biomech. Mar 1992;25(3):311-318. Toussaint H, Roos P, Kolmogorov S.
4. The determination of drag in front crawl swimming. J Biomech. Nov 2004;37(11):1655-1663. Marinho D, Barbosa T, et al.
5. Can 8-weeks of training affect active drag in young swimmers. J Sports Sciences and Medicine. Mar 2010; 9, 71-78.